A RGBColorChooser shows three sliders that the user can manipulate to set the red, green, and blue, components of a color. A color patch shows the selected color, and there are three labels that show the numerical values of all the components. Values are in the range 0 to 255. The initial color is black.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 | /******************************************************* * MYCPLUS Sample Code - https://www.mycplus.com * * * * This code is made available as a service to our * * visitors and is provided strictly for the * * purpose of illustration. * * * * Please direct all inquiries to saqib at mycplus.com * *******************************************************/ import java.awt.*; import java.awt.event.*; import javax.swing.*; import javax.swing.event.*; public class RGBColorChooser extends JApplet implements ChangeListener { private JSlider redSlider, greenSlider, blueSlider; // For setting the color. private JLabel redLabel, greenLabel, blueLabel; // For displaying RGB values. private JPanel colorPatch; // Color patch for displaying the color. public void init() { /* Create JSliders with possible values from 0 to 255. */ redSlider = new JSlider(JSlider.HORIZONTAL, 0, 255, 0); greenSlider = new JSlider(JSlider.HORIZONTAL, 0, 255, 0); blueSlider = new JSlider(JSlider.HORIZONTAL, 0, 255, 0); /* Create JLabels showing current RGB and HSB values. */ redLabel = new JLabel(" R = 0"); greenLabel = new JLabel(" G = 0"); blueLabel = new JLabel(" B = 0"); /* Set the colors of the labels, and make them opaque */ redLabel.setBackground(Color.white); redLabel.setForeground(Color.red); redLabel.setOpaque(true); greenLabel.setBackground(Color.white); greenLabel.setForeground(new Color(0,150,0)); greenLabel.setOpaque(true); blueLabel.setBackground(Color.white); blueLabel.setForeground(Color.blue); blueLabel.setOpaque(true); /* Set the applet to listen for changes to the JSliders' values */ redSlider.addChangeListener(this); greenSlider.addChangeListener(this); blueSlider.addChangeListener(this); /* Create a JPanel whose background color will always be set to the currently selected color. Otherwise, the panel is empty. */ colorPatch = new JPanel(); colorPatch.setBackground(Color.black); /* Create the applet layout, which consists of a row of three equal-sized regions holding the JSliders, the Labels, and the color patch. The background color of the applet is gray, which will show around the edges and between components. */ setBackground(Color.gray); getContentPane().setBackground(Color.gray); getContentPane().setLayout(new GridLayout(1,3,3,3)); JPanel scrolls = new JPanel(); JPanel labels = new JPanel(); scrolls.setBackground(Color.gray); labels.setBackground(Color.gray); getContentPane().add(scrolls); getContentPane().add(labels); getContentPane().add(colorPatch); /* Add the JSliders and the JLabels to their respective panels. */ scrolls.setLayout(new GridLayout(3,1,2,2)); scrolls.add(redSlider); scrolls.add(greenSlider); scrolls.add(blueSlider); labels.setLayout(new GridLayout(3,1,2,2)); labels.add(redLabel); labels.add(greenLabel); labels.add(blueLabel); } // end init(); public void stateChanged(ChangeEvent evt) { // This is called when the user has changed the value on // one of the sliders. All the sliders are checked, // the labels are set to display the correct values, // and the color patch is set to correspond to the new color. int r = redSlider.getValue(); int g = greenSlider.getValue(); int b = blueSlider.getValue(); redLabel.setText(" R = " + r); greenLabel.setText(" G = " + g); blueLabel.setText(" B = " + b); colorPatch.setBackground(new Color(r,g,b)); } // end stateChanged public Insets getInsets() { // The system calls this method to find out how much space to // leave between the edges of the applet and the components that // it contains. I want a 3-pixel border at each edge. return new Insets(3,3,3,3); } } // end class RGBColorChooser |
